U.S. patent application number 10/046571 was filed with the patent office on 2003-05-29 for dialing programmed numbers from a mobile communication unit while internationally roaming.
This patent application is currently assigned to General Motors Corporation. Invention is credited to Mazzara, William E. JR..
Application Number | 20030100334 10/046571 |
Document ID | / |
Family ID | 21944153 |
Filed Date | 2003-05-29 |
United States Patent
Application |
20030100334 |
Kind Code |
A1 |
Mazzara, William E. JR. |
May 29, 2003 |
Dialing programmed numbers from a mobile communication unit while
internationally roaming
Abstract
Dialing numbers from a mobile communication unit (MCU) operating
in an international roaming mode is accomplished by using the SID
code of a base station communicating with the MCU for determining
the necessary prefixes to be appended to a number to be. A mobile
communication unit initiates communication between the MCU and a
base station having an SID code by dialing a number to be called by
the MCU, and receiving the SID code at the MCU. Once the MCU has
received the SID code, necessary calling prefixes, if any, are
determined for placing a call from the MCU to the number to be
called via the base station having the received SID code. Any
necessary calling prefixes are appended to the number to be called,
and a communication link is established between the MCU and the
number to be called, via the base station having the SID code. The
MCU may utilize a database of dialing prefixes required to dial the
number to be called from base stations having SID codes, and
determining the necessary calling prefixes by searching the
database for the received SID code by searching the database for
either or both of the received SID code or a range of SID codes
including the received SID code.
Inventors: |
Mazzara, William E. JR.;
(Drayton Plains, MI) |
Correspondence
Address: |
General Motors Corporation
Legal Staff, Mail Code 482-C23-B21
300 Renaissance Center
P.O Box 300
Detroit
MI
48265-3000
US
|
Assignee: |
General Motors Corporation
|
Family ID: |
21944153 |
Appl. No.: |
10/046571 |
Filed: |
October 26, 2001 |
Current U.S.
Class: |
455/552.1 ;
455/433; 455/564 |
Current CPC
Class: |
H04M 1/27485 20200101;
H04M 1/724 20210101 |
Class at
Publication: |
455/552 ;
455/564; 455/433 |
International
Class: |
H04M 001/00 |
Claims
I claim:
1. A method for operating a mobile communication unit, the method
comprising: initiating communication between the mobile
communication unit and a base station having an SID code; receiving
the SID code at the mobile communication unit; dialing a number to
be called by the mobile communication unit; determining necessary
calling prefixes for placing a call from the mobile communication
unit to the number to be called via a base station having the
received SID code; appending necessary calling prefixes to the
number to be called; and establishing a communication link between
the mobile communication unit and the number to be called via the
base station having the SID code.
2. The method of claim 1 further comprising: creating a database of
dialing prefixes required to dial the number to be called from base
stations having SID codes; and wherein the step of determining
necessary calling prefixes for placing a call from the mobile
communication unit to the number to be called via a base station
having the received SID code includes searching the database for
the received SID.
3. The method of claim 1 further comprising: creating a database of
dialing prefixes required to dial the number to be called from base
stations having SID codes; and wherein the step of determining
necessary calling prefixes for placing a call from the mobile
communication unit to the number to be called via a base station
having the received SID code includes searching the database for a
range of SID codes including the received SID code.
4. The method of claim 1 further comprising: creating a database of
necessary dialing prefixes required to dial the number to be called
from base stations having SID codes; and wherein the step of
determining necessary calling prefixes for placing a call from the
mobile communication unit to the number to be called via a base
station having the received SID code includes searching the
database for the received SID, and if the received SID is not in
the database, searching for a range of SID codes encompassing the
received SID code.
5. A mobile communication unit for communicating with a number to
be called from the mobile communication unit via one of a plurality
of base stations each having an SID code, the mobile communication
unit comprising: a database for storing the number to be called by
the mobile communication unit, together with the SID code of each
of the plurality of base stations via which the mobile
communication unit may access the number to be called, and for each
SID code in the database a dialing prefix required for the mobile
communication unit to dial the number to be called via the base
station having that SID code; means for dialing the number stored
in the database to be called by the mobile communication unit;
means for initiating communication between the mobile communication
unit and the base station having the SID code; means for receiving
the SID code at the mobile communication unit from the base station
having the SID code; means for accessing the database and
determining the necessary calling prefix for placing a call from
the mobile communication unit to the number to be called via a base
station having the received SID code; means for modifying the
dialed number to form a modified dialed number including the
necessary calling prefixes; and means for establishing a
communication link between the mobile communication unit and the
number to be called via the base station having the received SID
code by transmitting the modified dialed number to the base station
having the received SID code.
6. The mobile communication unit of claim 5 wherein the means for
determining necessary calling prefixes for placing a call from the
mobile communication unit to the number to be called via a base
station having the received SID code includes means for searching
the database for the received SID code.
7. The mobile communication unit of claim 5 wherein the means for
determining necessary calling prefixes for placing a call from the
mobile communication unit to the number to be called via a base
station having the received SID code includes means for searching
the database for a range of SID codes including the received SID
code.
8. The mobile communication unit of claim 5 wherein the means for
determining necessary calling prefixes for placing a call from the
mobile communication unit to the number to be called via a base
station having the received SID code includes means for searching
the database for the received SID code.
9. The mobile communication unit of claim 8 wherein the means for
searching the database further includes means for searching the
database for a range of SID codes including the received SID
code.
10. A computer usable medium for operating a mobile communication
unit, comprising: computer readable code for initiating
communication between the mobile communication unit and a base
station having an SID code; computer readable code instructions for
receiving the SID code at the mobile communication unit; computer
readable code for dialing a number to be called by the mobile
communication unit; computer readable code for determining
necessary calling prefixes required for placing a call from the
mobile communication unit to the number to be called via a base
station having the received SID code; computer readable code for
appending necessary calling prefixes to the number to be called;
and computer readable code for establishing a communication link
via the base station having the SID code between the mobile
communication unit and the number to be called with necessary
calling prefixes appended.
11. The computer usable medium of claim 10 further comprising: a
database having necessary dialing prefixes required to dial the
number to be called via base stations having SID codes; and wherein
the computer readable code for determining necessary calling
prefixes required for placing a call via a base station having the
received SID code from the mobile communication unit to the number
to be called includes computer readable code for searching the
database for the received SID code.
12. The computer usable medium of claim 10 further comprising: a
database on computer readable medium having necessary dialing
prefixes required to dial the number to be called from base
stations having SID codes; and wherein the computer readable code
for determining calling prefixes necessary for placing a call from
the mobile communication unit to the number to be called via a base
station having the received SID code includes computer readable
code for searching the database for a range of SID codes including
the received SID.
13. The computer usable medium of claim 10 further comprising a
database on computer readable medium having necessary dialing
prefixes required to dial the number to be called from base
stations having SID codes; and wherein the computer readable code
for determining necessary calling prefixes required for placing a
call from the mobile communication unit to the number to be called
via a base station having the received SID code includes computer
readable code for searching the database for the received SID
code.
14. The computer usable medium of claim 13 wherein the computer
readable code for searching the database further includes computer
readable code for searching the database for a range of SID codes
including the received SID code.
15. A method for operating a mobile communication unit (MCU), the
method comprising: creating a database of access numbers to be
called from base stations having SID codes for accessing a desired
service via a received SID code; initiating communication between
the mobile communication unit and a base station having an SID code
in the database; receiving the SID code at the mobile communication
unit; requesting that the MCU access the desired service;
determining the access number in the database for accessing the
desired service via the base station having the received SID code;
and establishing a communication link between the mobile
communication unit and the determined access number in the database
for accessing the desired service via the base station having the
SID code.
16. A mobile communication unit comprising: means for creating a
database of access numbers to be called from base stations having
SID codes for accessing a desired service via a received SID code;
means for initiating communication between the mobile communication
unit and a base station having an SID code in the database; means
for receiving the SID code at the mobile communication unit; means
for requesting that the MCU access the desired service; means for
determining the access number in the database for accessing the
desired service via the base station having the received SID code;
and means for establishing a communication link between the mobile
communication unit and the determined access number in the database
for accessing the desired service via the base station having the
SID code.
17. A computer usable medium for operating a mobile communication
unit, comprising: computer readable code for creating a database of
access numbers to be called from base stations having SID codes for
accessing a desired service via a received SID code; computer
readable code for initiating communication between the mobile
communication unit and a base station having an SID code in the
database; computer readable code for receiving the SID code at the
mobile communication unit; computer readable code for requesting
that the MCU access the desired service; computer readable code for
determining the access number in the database for accessing the
desired service via the base station having the received SID code;
and computer readable code for establishing a communication link
between the mobile communication unit and the determined access
number in the database for accessing the desired service via the
base station having the SID code.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] This invention relates to mobile communication units, and
more particularly to operation of mobile communication units in an
international roaming mode.
BACKGROUND OF THE INVENTION
[0002] Mobile communication units (MCU's), such as cellular phones,
personal data assistants (PDA's), Global Positioning System (GPS)
devices, and on-board Vehicle Communication Units (VCU's), used in
conjunction with a Wide Area Network (WAN), such as a cellular
telephone network or a satellite communication system, have made it
possible for a person to send and receive voice communications,
data transmissions, and FAX messages from virtually anywhere on
earth. Such communication is initiated at the MCU when it is turned
on, or by entering a phone number to be called, or in many cases,
by pressing a preprogrammed button on the MCU or speaking a voice
command causing the MCU to automatically complete the process of
dialing the number to be called. A radio communication link is
established between the MCU and a Wide Area Network (WAN), using a
node of the WAN in the vicinity of the MCU.
[0003] In cellular telephone systems, a node is commonly referred
to as a "cellular base station." For ease of understanding, the
following description and illustrations of my invention will use a
WAN in the form of a cellular telephone system, and the node will
be represented by a cellular base station. Once the radio
communication link between the MCU and the cellular base station
has been established, the base station then utilizes a combination
of additional cellular stations, conventional telephone wire line
networks, and possibly even satellite systems to connect the MCU to
the number to be called.
[0004] For an MCU operating in a single country of origin, existing
communication systems are highly automated and capable of making
the complex connections between the MCU and the number to be called
in a manner that is, in most cases, virtually imperceptible to the
person initiating communication from the MCU. Indeed, MCU users
expect and demand that they be able to place a call with little or
no effort on their part, beyond dialing a phone number, or pressing
a speed dial button.
[0005] For MCU's which must operate in more than one country or
along the border between two countries, however, existing systems
have not been capable of delivering the same level of effortless
connection because the connections required to complete the call
include one or more international connections. The calling prefixes
that must be appended to the basic number to be called are
different for international direct dial (IDD) than the prefixes
required for national direct dial (NDD) or local calls.
International calls typically require that additional prefixes
including a country and city code of the number to be called be
appended to the basic number, and in some cases also require that
some of the prefixes used for national direct dialing be dropped
when dialing an international call.
[0006] For an MCU operating in an international roaming mode, there
are literally thousands of possible prefix requirements which must
potentially be dealt with, dependent upon which country the MCU,
the cellular and wire line carriers, and the number to be called
are located with respect to one another. Dialing formats vary
considerably from country to country, making it very difficult to
know exactly how the number to be called must be modified when
making a call between a particular pair of countries. Prior MCUs
and cellular systems have left the burden of dealing with the
changes in prefixes required for international dialing with the
person making the call.
[0007] Adding to the burden on the person using the MCU in an
internationally roaming mode, there are special arrangements
between some countries which are exceptions to general rules
governing the circumstances under which IDD prefixes must replace
NDD prefixes. For example, an MCU which can be used in a
non-internationally roaming mode to place calls to numbers within
the United States, can also place calls to Canada, Puerto Rico, and
many Caribbean Countries using NDD prefixes in the same manner used
for dialing a number within the United States, rather than IDD
prefixes. IDD prefixes will be required, however, if the same MCU
is used to place a call to a number in Mexico, or other countries
of the world.
[0008] The burden of dealing with calling prefixes in international
calls is not unique to the use of MCU's. Any person wishing to
place an international call from either an MCU or a standard phone
must deal with the potential need for appending the necessary
prefixes to the number to be called, or replacing NDD prefixes with
IDD prefixes. Operating an MCU in an internationally roaming mode
imposes an additional level of difficulty to placing an
international call, however, due to the manner in which cellular
telephone networks operate.
[0009] At some point in the process of connecting the MCU to the
number to be called, the MCU must establish a radio-telephone link
to a cellular base station. The cellular base station will then
establish a communication link to the number to be called, using
cellular and wire-line networks. Where the MCU connects to a
cellular base station in another country, while operating in an
internationally roaming mode, a call which would normally not
require the entry of additional international dialing prefixes if
the MCU were operating in its country of origin, becomes an
international call. Somehow the cellular system, or the person
using the MCU must recognize that this situation exists, and enter
or modify the calling prefixes to complete the call.
[0010] In normal operation of an MCU within its country of origin,
there is no need for the person using the MCU to be aware of the
location of the base station via which their call is being
connected. Accordingly, existing cellular systems make no provision
for the MCU user to know which base station their call is being
routed through. There is therefore no way that the user can
determine what prefixes are needed for communication through a
particular base station.
[0011] Even where the MCU has the ability to know its own location
in the world, via a direct link to a GPS system, for instance, the
location of the base station must also be ascertained, and then the
necessary prefixes, if any, must be determined and appended to the
number to be called. A GPS system will not provide this
information.
[0012] The difficulties involved in dealing with international
calling are so burdensome that people traveling abroad often leave
their own MCU at home and rent special equipment from services
which specialize in providing international mobile communication
services. For some users this may provide an acceptable solution.
But for owners of MCUs which are mounted in vehicles to provide a
variety of on-board services to users while traveling, such as
OnStar, from General Motors, the need to rent special equipment for
international travel is particularly aggravating and
inconvenient.
[0013] What is needed, therefore, is the capability to place calls
from an MCU operating in an internationally roaming mode without
requiring the person placing a call to know the location of the
cellular base station, or to memorize and append necessary calling
prefixes for international calls to the number the person wishes to
call. This need is particularly acute for MCU's mounted on-board in
vehicles which are commonly operated while the vehicle is in motion
where the additional steps of entering necessary prefixes in an
internationally roaming mode, could greatly diminish the ability to
use MCU based navigational aides, and cause unreasonable
frustration and distraction of the vehicle operator.
SUMMARY OF THE INVENTION
[0014] My invention provides a solution to the problems discussed
above through utilization of the System Identifier code (SID),
which is assigned to each cellular base station in the world. The
SID is broadcast to the MCU as part of initiating a communication
link between the MCU and the base station, but is not revealed to
the user of the MCU. SID codes are generally unique to each market,
but all stations within a given country are generally assigned a
SID within a given range of SID numbers. For example, base stations
in the United States, Canada, and Mexico are generally assigned SID
codes in the ranges of 1 through 15999, 16000 through 16999, and
24000 through 24999, respectively. Once the location of the base
station is ascertained from the SID code, it can also be
ascertained what necessary calling prefixes are required to place
an international call via the base station having that SID to
numbers located in that country or other countries, from an MCU in
an international roaming mode.
[0015] One form of my invention provides a method for operating an
MCU in an international roaming mode by determining the necessary
prefixes to be appended to a number to be called from the SID of a
base station communicating with the MCU.
[0016] My invention may be implemented in various automated
methods, apparatus, and software forms allowing a person wishing to
place a call from an MCU in an internationally roaming mode to
conveniently deal with the tens of thousands of potential SID
codes, anomalies in assignment of the SID codes, and the many
potential combinations of location of the MCU and the base station,
together with the many different potential combinations of
international dialing prefixes and country codes.
[0017] My invention provides the needed capability to place calls
from an MCU operating in an internationally roaming mode without
requiring the person placing a call to know the location of the
cellular base station, or to memorize and append necessary calling
prefixes for international calls to the number the person wishes to
call, through inclusion in the MCU of a database having a
tabulation of numbers to be called from the MCU, together with the
calling prefixes which must be appended to each of the numbers in
the database when a call is made from the MCU to a number in the
database via a cellular base station having a particular System
Identification (SID) code. My invention thus allows a call to be
made from an MCU operating anywhere on earth to a number which may
be in another country without the user having to perform any tasks
beyond what they would perform to place a call to that same number
while the MCU was operating in a normal, non-international roaming
mode.
[0018] According to one form of my invention, a method for
operating a mobile communication unit includes initiating
communication between the mobile communication unit and a base
station having an SID code, and receiving the SID code at the
mobile communication unit. A number to be called is then dialed or
selected from speed dial list. The MCU determines what calling
prefixes, if any, are required for placing a call from the mobile
communication unit to the number to be called via a base station
having the received SID code. Any necessary calling prefixes are
appended to the number to be called, and a communication link is
established between the mobile communication unit and the number to
be called, via the base station having the SID code.
[0019] My method may include creating a database of dialing
prefixes required to dial the number to be called from base
stations having SID codes, and determining the necessary calling
prefixes by searching the database for the received SID code. My
method may also include creating a database of dialing prefixes
required to dial the number to be called from base stations having
SID codes, and determining the necessary calling prefixes by
searching the database for a range of SID codes including the
received SID code.
[0020] My invention also includes apparatus and software for
carrying out the methods of my invention.
[0021] The foregoing and other features and advantages of the
invention will become further apparent from the following detailed
description of the presently preferred embodiments, read in
conjunction with the accompanying drawings. The detailed
description and drawings are merely illustrative of the invention
rather than limiting, the scope of the invention being defined by
the appended claims and equivalents thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a block diagram depicting an exemplary MCU in
accordance with my invention;
[0023] FIG. 2 is a block diagram depicting an exemplary embodiment
of code on a computer readable medium in accordance with my
invention; and
[0024] FIG. 3 is a flowchart depicting an exemplary method for
operating an MCU in internationally roaming mode in accordance with
my invention.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0025] FIG. 1 shows a mobile communication unit (MCU) for an
exemplary embodiment of my invention. The MCU 10 communicates with
a number to be called 12, via a radio-telephone link 13 with a base
station 14 having an SID code, and a wire-line connection 16
between the base station 14 and the number to be called 12.
[0026] The MCU 10 includes a transmitter/receiver 18, an
input/output device 20, and database 22, connected to a central
processing unit (CPU) 24. The input/output device 20 may take many
forms known in the art, including an alpha-numeric telephone
keypad, a touch screen, speed dial buttons, a data port, an LCD
display, or a voice actuated command apparatus.
[0027] The database 22 is adapted to store the number to be called
12, together with the SID code of the base station 14, and one or
more dialing prefixes required for the MCU 10 to dial the number to
be called 12 via the base station 14. It is contemplated that the
database 22 may be adapted to receive and store a plurality of
numbers to be called, with each number being stored together with a
plurality of SID codes representing a plurality of base stations 14
through which the MCU 10 might access each number to be called, and
for each of the plurality of SID codes for each number to be called
a dialing prefix required for the MCU 10 to dial the number to be
called via the base station having that SID code.
[0028] The input/output device 20, CPU 24, and transmitter/receiver
18, in combination, provide means for dialing a number stored in
the database 22 to be called by the MCU 10, and means for
initiating communication between the MCU 10 and the base station 14
having the SID code. The transmitter/receiver 18 and CPU 24, in
combination, provide means for receiving the SID code at the MCU 10
from the base station 14.
[0029] The CPU 24 includes means for accessing the database and
determining the necessary calling prefix for placing a call from
the MCU 10 to the number to be called 12, via the base station 14
having the received SID code. The CPU 24 also provides means for
modifying the dialed number to form a modified dialed number
including the necessary prefixes. The means for accessing the
database and determining the necessary calling prefixes may include
means for searching the database 22 for either or both of the
received SID code, or a range of SID codes including the received
SID code.
[0030] The combination of the input/output device 20, the CPU 24
and the transmitter/receiver 18 provide means for establishing a
communication link between the MCU 10 and the number to be called
12 via the base station 14 having the received SID code, by
transmitting the modified dialed number to the base station 14
having the received SID code.
[0031] As shown in FIG. 2, my invention may also be implemented in
a code 26 on computer readable medium for operating an MCU 10. The
code 26 includes instructions for initiating 28 communication
between the MCU 10 and a base station 14 having an SID code, and
for receiving 30 an SID code from the base station 14. The code 26
also includes instructions for dialing/selecting 32 a number to be
called by the mobile communication unit, instructions for
determining 34 the necessary calling prefixes required for placing
a call from the MCU 10 to the number to be called 12, and
instructions for appending 36 the necessary calling prefixes to the
number to be called 12. The code 26 further includes instructions
for establishing 38 a completed connection between the MCU 10 and
the number to be called 12 via the base station 14 having the SID
code.
[0032] The code 26 may also include a database 22, on computer
readable medium, having necessary dialing prefixes required to dial
the number to be called 12 via the base station 14 having the SID
code, and the instructions for determining 34 the necessary calling
prefixes may also include instructions for searching the database
22 for either or both of the received SID code, or a range of SID
codes including the received SID code.
[0033] FIG. 3 depicts a method 40 for operating an MCU 10 by
initiating 42 communication between a base station 14 having an SID
code, and for receiving 44 the SID code from the base station 14.
The method 40 further includes instructions for dialing 46 a number
to be called 12 by the MCU 10, and determining 48 additional
dialing prefixes required for the MCU 10 to place a call to the
number to be called 12 via the base station 14 having the received
SID code. The method further includes appending 50 the required
additional dialing prefixes to the number to be called 12, and
establishing a complete connection between the MCU 10 and the
number to be called 12 via the base station 14 having the received
SID code. The method 40 may also include creating a database 22 of
dialing prefixes required to dial the number to be called 12 from
the base station having the received SID code, and the step of
determining 48 necessary calling prefixes may include searching the
database 22 for either or both of the received SID code, or a range
of SID codes including the received SID code.
[0034] The configuration of the database 22 and the methods of
determining the required prefixes will vary considerably, depending
on the type and location of the number to be called 12, the country
of origin of the MCU 10, the location of the MCU 10 and the base
station 14, and the preferences of the user. For purposes of
enhancing understanding of my invention, I have provided three
examples, designated as Example A, B, and C, of possible
embodiments of a database according to my invention.
[0035] It should be noted that, although the SID codes and numbers
used in Examples A through C are similar in appearance and
numerical value to those used in actual cellular systems, the
particular values listed in Examples A through C have been
arbitrarily selected to enhance understanding of my invention, and
are not intended to be limiting. I have also purposely ignored
certain anomalies that exist in actual cellular systems, such as
the existence of actual base stations in Mexico City which are
assigned SID codes of 1525, which is not within the range of SID
codes generally used in Mexico, and would normally indicate base
station within the range assigned to stations in the United States.
Those having skill in the art will readily recognize that my
invention provides a convenient method for dealing with such
anomalies in an MCU, a method, or in software, according to my
invention.
[0036] Example A, below, illustrates the construction and contents
of a database 22 for an MCU 10 having set up for national direct
dial local and long distance service in the United States, and for
international roaming in Canada and Mexico.
EXAMPLE A
Automated Direct Dialing of Numbers from an Address Book in an MCU
Having Local, National Long Distance, and International Long
Distance Numbers
[0037]
1 CELLULAR SPEED DIAL # TO BE BASE STATION DESIGNATION CALLED SID
LDD PREFIXES NDD PREFIXES IDD PREFIXES 1 221-1658 15560-15570
221-1658 N/A N/A " 1-15559 & N/A 1-888-221-1658 N/A 15571-15999
" 16000-16999 N/A 1-888-221-1658 N/A " 24000-24999 N/A N/A
0-1-00-888-221-1658 2 1-888-221-1658 1-15999 N/A 1-888-221-1658 N/A
" 16000-16999 N/A 1-888-221-1658 N/A " 24000-24999 N/A N/A
0-1-00-888-221-1658 3 0-52-262-958 1-15999 N/A N/A 0-52-262-958 "
16000-16999 N/A N/A 0-52-262-958 24000-24999 N/A 01-262-958 N/A 4
262-958 24010-24012 262-958 N/A N/A " 24000-24009 & N/A
01-262-958 N/A 24013-24999 " 1-15999 N/A N/A 0-52-262-958 "
16000-16999 N/A N/A 0-52-262-958
[0038] The first number, designated as Speed Dial #1, is set up to
be called as a local number, without NDD prefixes, in the United
States via cellular base stations in the local service area of the
cellular service provider, having SID codes in the range of 15560
through 15570. Because this is local service, the database shows
that no NDD or IDD prefixes need be appended for calls to the base
stations having SIDs in the range of 15560-15570.
[0039] If Speed Dial #1 is called from within the US, but outside
the local service area, the MCU would be connected through a base
station having an SID code in the range of 1-15560 or 15571-15999,
and the database shows that the number to be called would have to
be modified to include the NDD prefix and area code of the number
to be called. This same modified number would be required if the
MCU is connected via a base station in Canada, having an SID in the
range of 16000-16999, because the United States and Canada both
require the same NDD prefix arrangement.
[0040] If Speed Dial #1 is called via a base station in Mexico,
however, the base station will have an SID code in the range of
24000-24999, and the database indicates that the NDD is replaced
with an IDD prefix and the country code for the United States.
[0041] The second number, designated Speed Dial #2, is set up to be
a national long distance call within the United States. The Local
Direct Dial (LDD) column is therefore blank, and the NDD and IDD
columns indicate the required prefixes for placing calls to base
stations located in the US, Canada, and Mexico.
[0042] Speed Dial #3 is set up to be an international long distance
call to Mexico from the MCU when communicating through base
stations having SID codes in the range of 1-15999 in the United
States or base stations having SID codes in the range of
16000-16999 in Canada. When the MCU is operating through a base
station in Mexico having an SID code in the range of 24000-24999
the IDD prefix is replaced with an NDD prefix for Mexico.
[0043] Speed Dial #4 is set up to be a local call when the MCU is
connecting through a base station in Mexico within a local service
range having a SID code in the range of 24010-24012, and a national
long distance call when the MCU is connecting through a base
station in Mexico, outside the local service area, having an SID
code in the range of 24000-24009 or 24013-24999. For calls in the
local area, the LDD prefixes are used, and for calls outside the
local service area in Mexico, the NDD prefixes are used. For calls
to Speed Dial #4 from the US or Canada, the MCU will connect via a
base station having an SID code in the range of 0-15999, and
16000-16999 respectively, and the database shows that the IDD
prefixes must be used.
[0044] It is contemplated that that the MCU may incorporate means
for selecting the least costly number, i.e. LDD versus NDD service
for example. It is also understood that the contents of a database
according to my invention may vary considerably from the format
used in Example A. It may be desirable to store only the prefixes
themselves, and have the MCU remove any prefix from the "number to
be called" as it is entered into the database separate from an SID
code. The means for accessing the database and determining the
necessary calling prefixes may include means for searching the
database 22 for either or both of the received SID code, or a range
of SID codes including the received SID code.
[0045] Example A is an illustration of a database that can accept a
variety of call types. For some embodiments of my invention,
however, it may be desired to use only one type of number, perhaps
a series of national toll free long distance numbers within the
country of origin. A more compact database, as illustrated in
Example B below, may be used in such embodiments.
EXAMPLE B
Automated Direct Dialing of Numbers from an Address Book in an MCU
Having Only National Long Distance Numbers
[0046]
2 CELLULAR SPEED DIAL # TO BE BASE STATION DESIGNATION CALLED SID
NDD PREFIXES IDD PREFIXES 1 1-888-221-1658 1-15999 1-888-221-1658
N/A " 16000-16999 1-888-221-1658 N/A " 24000-24999 N/A
0-1-00-888-221-1658 2 1-888-221-1659 1-15999 1-888-221-1659 N/A "
16000-16999 1-888-221-1659 N/A " 24000-24999 N/A
0-1-00-888-221-1659 3 1-888-221-1660 1-15999 1-888-221-1660 N/A "
16000-16999 1-888-221-1660 N/A " 24000-24999 N/A
0-1-00-888-221-1660
[0047] The database of Example B is set up to include only three,
toll-free long distance numbers, accessible with NDD prefixes when
the MCU is connected via a base station in the United States and
Canada, and accessible with IDD prefixes when the MCU is connected
via a base station in Mexico. There are no local number
alternatives in any country in the table.
EXAMPLE C
Automated Direct Dialing Access to Services Using a Listing of
Local Numbers for Various SID Codes from a Database in an MCU
[0048]
3 LDD SERVICE DESIGNATION SID NUMBER RED BUTTON - EMERGENCY 1-15999
221-1658 ASSISTANCE 16000-16999 695-4021 24000-24999 262-958 BLUE
BUTTON - INFORMATION 1-15999 221-1659 16000-16999 695-4022
24000-24999 262-959 WHITE BUTTON - COMMUNICATION 1-15999 302-2345
16000-16999 562-1111 24000-24999 232-596
[0049] In Example C, the MCU has three push buttons for three types
of services respectively that may be desired by the user. The
database has a listing of local numbers for accessing each type of
service through a node of a wide area network having a particular
SID code. For simplicity of illustration, only one local number has
been illustrated for a range of SID codes, but in practice the
database may include a large number of SID codes, each linked to a
particular local access number.
[0050] Specifically, Example C illustrates the manner in which a
user may access a local number for a desired service through
stations having SID codes allocated to markets in the United
States, Canada, or Mexico by simply pressing a colored button. A
user needing to access emergency services, for example, would
simply press the red button of the MCU. The MCU would select the
appropriate local number from the database for the SID code of the
station through which communication would be established, and
complete the connection.
[0051] Stated another way, all the user has to do is to indicate
what service is needed or desired, and regardless of what country
the user is in at that time, the MCU will select a local access
number from the database and complete the connection with that
local number. The user need not be concerned about how to access
the desired service in each country, or be distracted from driving
or dealing with an emergency, because the MCU does all the work of
figuring out how to make the connection to a local number in that
country.
[0052] From the foregoing description, it has been shown that my
invention provides the needed capability to place calls from an MCU
operating in an internationally roaming mode without requiring the
person placing a call to know the location of the cellular base
station, or to memorize and append necessary calling prefixes for
international calls to the number the person wishes to call. My
invention thus allows a call to be made from an MCU operating
anywhere on earth to a number which may be in another country
without the user having to perform any tasks beyond what they would
perform to place a call to that same number while the MCU was
operating in a normal, non-international roaming mode.
[0053] Although the forgoing description has utilized certain
exemplary embodiments of my invention, various changes and
modifications can be made without departing from the spirit and
scope of the invention. The scope of the invention is indicated in
the appended claims, and all changes that come within the meaning
and range of equivalents are intended to be embraced therein.
* * * * *